The latest versions of UBI usually include it as a replacement for some social service payments like EI. However, the initial idea behind UBI was to account for automation replacing a lot of jobs that will result in many more people than jobs available. I don't think that $1000 was ever intended to cover all social services.
Locke mentioned the ensuing madness from countries that have tried UBI. That's hyperbolic and there are mixed results, as you'd expect.
https://www.vox.com/future-perfect/2...income-ubi-map